Door latch mechanism



L. F. DUSING I 2,772,905

DOOR LATCH MECHANISM Filed July 14, 1954 Dec. 4, 1956 fj i. 3

- INVENTOR. E 'd, '4 LEON E DUS/NG @wa, MMYQz I A7 7 ORNEYS.

- 2,772,905; C noon LATCHVMECHAQNI'SM. 1

i Leon F. Dusing, Kenmore, N. Y., assignor to Dusing and Hunt, Inc.,Buffalo, N. Y.

Application July 14, 1954, Serial Ne. 442,,219

7; Claims. c1. 292

YThe'present invention relates generallyto multiple latch door lockingarrangements, and more particularly is ,directed to a spring latcharrangement which is especially adapted for holding massivefire-resistant doors in closed position even under extreme temperatureconditions} 'Anobject of this invention is to provide a multiple springlatch arrangement for mounting along the edge of a door, wherein a mainlatch portion thereof will be arranged to be mounted in outwardly,ofisetrelation as compared to a plurality of co-operating spacedauxiliary latch units, the auxiliary latch units being operable uponactuation of the main latch units to retract for clearing theirrespective door jamb striker plates, f whereby all frictional forcesincidental to locking ofthe' spring latches will be concentrated in thearea of the main spring latch'to provide a relatively easily ope'rableand etficient door latching mechanism as compared with prior, artmultiple spring latch mechanisms of this type. Another object of thisinvention is to provide latch operating means in a multiple spring latcharrangement of theaforesaid type including latch interconnection meansadapted to be automatically 'disengagedfromeach ofthe respective latch'meansunder pre-determined elevated temperature conditions in order topreclude .the possibility of such latch means being forced intodooropeningrposition as a result of wrapping'of the connecting lihkagedue to attainment of such elevatedtemperature eonditionsLf a v.1 I Stillanother 'object'of this invention is to' provide a multiple spring doorlatch arrangement embodying an offsefactuating unit, in combination withlatch operating means provided with latch interconnection means of theaforesaidtype. a a n 1 Other. objectsfland jadvantages of this inventionwill appear in thesp'e'cification hereinafter. In the drawing: A I, QFig/[shows a general perspective View of a fire dqor embodying one formof the present invention; 1"

Fig.1 2 is, a fragmentary end levational view of: the devicepshpwn'inFig, l", being'pa'rtially insection tomore clearly illustrate latchingmechanism of the present invention; t JIFig, 3 isa fragmentarysideelevational view of the .device shown in Fig. 2 with the latch mechanismcasing being omitted; and, z 1

, Fig. 4 is a,fragmentarysectional.view takengen'er'ally along the lineIv -IV. of Fig. 3. l J l f keferring nowtmore particularly to thedrawing, the embodiment of the invention illustrated therein comprises.a fire-resistant door ,10, a main latch mechanism 12, supplementallatchmechanisms, 14 311(116, latch connection rneans 18, latch'handleslfl and22, and a latch casing ,24' Figs. 1, 2 and 3.). t 1 f The main latch.mechanism 12 is show'n to be mounted pa a'flafnged supportmember 26 by'a'ffixation to a central 'its fps o .2 reof t m m b ut bymeans'of aplurality" of screws 29 to the upper portion Patented Dec. 4, H256 ofthe door 10 adjacent a side-edge thereof (Fig; 3). A main latch casingportion 30 will be secured to the offset portion 28 by means of aplurality of screws 32forfurther supporting the main latch asmoreparticularly described hereinafter. t t The 'upper portion of thecasing-30 is provided with a crank pin 34 fixed in the walls thereof forthe purpose of pivotally mounting a bolt-actuating bell crank-'36; Thebell crank 36 has a bolt-actuating arm 38 arranged to depend downwardlybetween -the inner side portion 39 of a main bolt member 40 and theouter face of the sup"- port flange portion 28. An opposed crankarm-420i the crank36 extends away from the pin 34 to provide a crankactuating arm portion. t? v These crank arm portions 38' and 42 arelimited against further clock-wise movement from the: position 'shown'inFig. 3 by means of a casing-abutment portion 43 as more fully discussedbelow. l

The main bolt member 40 is shaped in the customary manner in order tohave a cam surface portion 44 at its outer end for hitting against adoor jamb striking plate 81 (shown in dotted lines in Fig. 2) to cam thebolt into re tracted position,the back end portion of the main bolt 42being cut away to provide a recess 44 therein into which extends one endof a compression spring supporting member 46 having its opposite endfixed to the side wall of the casing 30 (Fig. 3) A compression springmember ,48 fits over the support member 46 so as to. be compressedbetween the side wall of the casing 30 and the base portion of therecess 44 to resiliently urge the main bolt 40 outwardly into itsstriker plate engaging position. I

The inner side portion 39' of the main bolt 40 is'pro vided with ashoulder portion as indicated at 50 in ablatting relation to the rearedge portion of the depending crankarm 38, and also a protuberance 52 inspaced re1ation to the, portion 50 for abutting the ,front edge portionof the crank arm 38 (Fig. 3) whereby the main bolt 40 will be actuatedbetween open and closed positions responsive to rotary movements of thecrank arm 42 The abutment portion 43 of the crank 36 limits pivotalmovement of the crank in a, rotary clock-wise: direction so as to retainthe main bolt 40 against further, movement outwardly as a result of theresilient surge of the spring 48'and thereby will maintain the bolt inassembled relation while being free to be cammed backwardly during adoor closing operation as by striking the keeper plate 81.

The latch connection mechanism 18 will memes a crank actuating member 54disposed generally parallel to the edge of the door 10 preferablyinwardly of the latch units 12, 14 and 16 as shown in Figs. 2 and 3. Themember 54 is of generally elongate form bent at its upper end into anofiset portion 54(a) as more particularly noted below (Figs. 2 and 3). i

The latch units Hand 16 will be constructed in a manner similar to thatdescribed above for the main latch unit 12 with the exceptions notedbelow. Thus, the latch units 14 and 16 will include latch housings56-58; supplemental latch bolts 60-62; compression latchbolt springs64-66; pivotally mounted bell cranks 67-968 each having crank armportions 72 and 74 and a casing abutment portion 76; the latch boltseach having a shoulder 78 and a protuberance 79 f onve'njgaging thecrank arm portions 72 (Figs., 2 and 3); these partshe'irlg constructedand arranged'in a manner similar to their corresponding parts asdescribed above for the main latch 12. One exception from thearrangement of the main latch 12 is that the housings 56 and 58"of thelatches 14' and 16 preferably will be aflixed directly "to the centerand lower portions of the door'10 insubstantially vertical alignmentwith the unit 12 but'being' ofis'e't from this unit'in adirection'toward the mounting surface Another cxoeption. fromtheaarrangemeutg of; the main latch; 12 isthat. the latch}, bolts 60Jand62of; the supplemental latchesl4 and. ;1f6 ;-will be; provided with;integral springmountiugtpedestal portions -46(.a) and; 56th) ex tendingrearwardly from cut away recesses 44(2z and.

44.(b): in. the-back end thereof; for. supportingthe compression-,springs'6 4,-66 in place; of mounting these pedestal portionsintegrally with their. casings. asin the case, of: the main.-latch 12,,These pedestals .'46( -a fand 46( 2) willextendthroughnheirrespectivecasings 5 653 for'abutme ntaga nst a l nge p o o H r se angle-iron;tabs;46(c);and- 46(d) fixedto the member 54 aszshown. iu.Fig, ,3. :Thusthe supplemental-latch bolts '60 and 62 will be precluded fromretractionagainst .the

resilienturge'ot, their springs 64-66 exceptuponractuationbfthe-mainlatch mechanism 12 into retracted position. ,7.

As shown most clearly in Fig. 3, the crankconnecting member 54 -willbepivotally connected, in a manner maaob more fully described below, atspaced positions along 7 its length to the outer ends of the respectivebell crank arrnportions 36-74- -74:of the respective latch mechanisms12, 14 and 16. Of course, it.will be appreciated as is commonly known inthe art that the handle members and 22 will be mounted on a spindlemember 80 titted through the door 10 andkeyed by way of example 7 to thebell crank 7 f the latch unit 14. ThusQrotation of the handle members 20or 22 will simultaneously cause all of the bell cranks to retractagainst the urge of'their respective springs 50, 64 and 66 by virtue oftheir interconnection through the mediumof the member 54. for'thepurpose of manually opening and closing a door, the handles and thelatch-bolts of the latch arrangement automatically. returning to theirnormal positions upon release thereof.

v It will be appreciatedto be a particular feature of the presentinvention that by virtue of the offsetmounting of the. main bolt 40, thecam portion 44 thereof will strike thedoor striker. plate portion of'itsrespective keeper plate 81 (shownin dotted linesin Fig. 2) in advance ofthe arrival jotthe supplemental bolts and 62, ofthe latch units 14 and16 at their respective keeper 'plates'81(a) and 81(b) (also shown indotted lines in Fig. 2). Thus, forfexa mple, the intertia ofthe doorwhen swung toward closed, position will provide siiflicient force tocause the suitable means so asto be integral with the member The leadfill 88 is provided with wear-bushing 90substantially centrallythereofjfor supporting a connecting pin 92 in journaled relationtherethrough. The pin 92 is headed at one end as shown at 94 forpivotally connecting the crank arms as for example the arm portions 74(Fig. 4), to the member'54 andwill be provided with a cotter pin 96 atits opposite end for retaining the parts in assembled-relation.

Thus upon attainment of the preselected melting point of the above fill8 8, the pivotal inte'rconne'ctiojn between the member 54 and the bellcranks will be released. Hence,-in the event-of a fire,'or extreme'heat-condition in the vicinity of doors embodying-the invention, themultiple latches of the present latching arrangement will becomeindividually operable latch units whereby warpage of the member 54 willnot be likely to cause the latch bolts toretract to permit the door toopen atanjnopportune time before the fireor extreme temperaturec'o'ndition is brought under. control.

While one particular embodiment of the presentinvention has. been shownand particularly described in detail herein, it will beunderstood thatthe invention is not so limited but thatvarious changes and modifications may be made therein without 'departing'from the spirit oftheinvention or thescope of the appended claims.

What is claimed is:

V 1. In a fire-door construotion, a multiple latch bolt door lockingrarrangement comprising .a' main latch bolt assembly operably connectedto. a plurality of supplemental latch bolt. assemblies arranged inventical=lyaligned relation adjacent the-edge'of afi re-door, each ofthe latch. bolt assemblies having resiliently outwardly urgedousmovements thereof, said "main latch bolt assembly being offsetlaterally away from the inside dooriface out of alignment wi-tht-hesupplemental latch bolt assemblies whereby the bolt means of said mainlatch boltassembly will strike its keeper plate in advance of thearrival of the bolt means of the,supplernental latch, boltassembliesstriker plate portion of the keeper plate 81. to bear against :the camportion 44 of the main boltQ40 to overcome the .resilient'urge of thecompression spring 48* acting thereon and also to simultaneously pivot,the bell crank member 36 about its pivotal mounting 34-for actuating themember 54to simultaneouslyrotate the bell crank members 7.4,.of thelatch devices14 and 16 and thereby, to retract their respective latchbolts 60 and 62 in advance of their arrival at the door jamb.

, Therefore, by virtue of the above described arrangement,.f'rictionalcontacts between the bolts,60 and 62 and their respective keeperplates"811(a) and, 81(-b) will be avoided to provide an improved highlyvel'licient multiple bolt door locking arrangement in-which the; numberof ivear'points along the'door jamb will be reduce'd, This will, ofcourse, reduce maintanence costs and will also increase the useful lifeof locking arrangementsembody a low meltingrmaterial 88, as forexamplelead; by any gate slots 82,84: and, 'These slotswill be filled with at'theirrespective' keeper plates, whereby the bolt means in said mainlatch bolt assembly will be retractedupon striking its keeper plateand-thereby simultaneously retract the bolt means of thesupplemental'latch bolt ass-em bl-iesout of contactwith their'respectivekeeper plates,

.2. In a ike-door construction, a multiple bolt door lockingarbangement'including a'm'ain bolt, a plurality of supplemental boltsarranged in vertically aligned re lFa-tion adjacent the edge of afire-door, resilient means urging said bolts into door closingposit-ion, aplurality of bell crank means being pivotally mounted inconnection with said door bolts for movements therewith, means pivotallyinterconnecting said bell .crank'means so that movement of one of saidbolts against the urge ofsa'id resilient means will correspondinglyretract the other bolts, said main bolt being mounted" inwardly relativeto-the other bolts so :as tostrike its door jamb keeper plate in advanceof the arrivalo'f the other boltsjwhereby the other bolt means Will'besimultaneously retracted for fitting into their respective keeperplates.

' 3.I'n a fire-doorconstructiomfin combination, apl-urality ofspring-pressed bolts in operablyin'tenconnected relation for.simultaneous retracting movements "responsiye' to actuation of 'any onefthereofijdoor jamb keeper plates having a bolt striking portion, oneof'saidbolts being positionally offset out 'of' alignment with the re-'maining latch bolts in order that the formenw-il l' strike pec ve.str knsizd t n o o u e sai fothe at bolts-toretraet tocleartheir'respeetivekeeperplate striking portions incidental to a doorclosing operation so as to be fitted into their keeper plates withsubstantially no frictional contact therebetween.

4. In a fire-door construct-ion provided with a plurality of springlatch bo'lt means at spaced intervals along a side edge thereof, bellcranks each having one arm in engagement with a corresponding boltmeans, the other arms of said bel-lcranks being pivot-ally connected toan elongate link member by means of a pin member journalled in a bushingsupported in a bushing support portion of said link member, the bushingsupport portion having a preselected melting point, said bolt meansbeing linked for simultaneous operation except upon attainment of saidmelting point of said bushing support portion whereby Warping of saidlink member due to elevated temperatures will not actuate said boltmeans to open the fire-door.

5. In a fire-door construction, a plurality of spring latch bolt meansmounted at spaced intervals along a side edge of a fire door, latch boltactuating means being in operably interconnected relation with each ofsaid latch bolt means for normal simultaneous actuation thereof, saidlatch bolt actuating means being arranged to embody a relatively lowmelting point material at spaced positions therein for supporting eachof the points of interconnection thereof with each of said spring latchbolts in order that upon occurrence of a temperature above said meltingpoint in the vicinity of the fire-door said supporting material embodiedin said member will melt to release said points of interconnection.

6. In a fire-door construction, .a multiple latch door lockingarrangement comprising a main bolt, a plurality of supplemental bolts,said bolts being arranged in vertically aligned relation adjacent theedge of a fire-door, keeper platemeans associated with the door jamb,spring means resiliently urging each of said bolts outwardly into doorclosing position, means pivota-lly interconnected to said bolts fornormal simultaneous actuation thereof,

said means being arranged to embody a low melting point material fornormally supporting the pivotal connections thereof with said boltswhereas upon the occurrence of temperatures above the melting point saidmaterial will melt to operably disengage said means from said bolts,said main bolt being offset out of alignment with the supplemental boltsin a direction away from the inside face of the door so that said mainbolt will strike said keeper plate means in advance of the arrival ofthe supplemental bol-ts thereat during closing of the door Whereby saidmain bolt will be retracted as a result of striking said keeper platemeans and thereby will simultaneously retract the supplemental bolts outof contact therewith.

7. In a fire-door construction, a plurality of spring pressed latchbolts mounted at spaced intervals along a side edge of the fire door, adoor ja-mb, keeper plates mounted in said door jamb in horizontalalignment with said latch bolts, one of said keeper plates beinglaterally offset in the direction of approach of said latch bolts, firstmeans associated With one'of said 'latch bolts for manual retract-ionthereof, second means connected to said bolts to normally permitsimultaneous actuating movements thereof responsive both to manualoperation of said first means and retraction of one of said bo'lts as bycamming it to retract incidental to its striking the ofiset keeper platein the door jamb, said second means incorporating a low melting pointmaterial arranged for normal support of the points of connection withsaid bolts and operable release thereof upon attainment of the meltingpoint temperature in the vicinity of the door.

References Cited in the file of this patent UNITED STATES PATENTS928,904 Cottrell July 20, 1909 1,006,211 Hermon Q. Oct. 17, 19111,086,125 Berry Feb. 3, 1914 1,951,628 Prost Mar. 20, 1934

